Ravin Balakrishnan
Has also published under the name of:
"R. Balakrishnan"
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Publications by Ravin Balakrishnan (bibliography)
» 2009 «
Vogel, Daniel, Cudmore, Matthew, Casiez, Géry, Balakrishnan, Ravin and Keliher, Liam (2009): Hand occlusion with tablet-sized direct pen input. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 557-566. Available online
“We present results from an experiment examining the area occluded by the hand when using a tablet-sized direct pen input device. Our results show that the pen, hand, and forearm can occlude up to 47% of a 12 inch display. The shape of the occluded area varies between participants due to differences in pen grip rather than simply anatomical differences. For the most part, individuals adopt a consistent posture for long and short selection tasks. Overall, many occluded pixels are located higher relative to the pen than previously thought. From the experimental data, a five-parameter scalable circle and pivoting rectangle geometric model is presented which captures the general shape of the occluded area relative to the pen position. This model fits the experimental data much better than the simple bounding box model often used implicitly by designers. The space of fitted parameters also serves to quantify the shape of occlusion. Finally, an initial design for a predictive version of the model is discussed.”
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Bi, Xiaojun and Balakrishnan, Ravin (2009): Comparing usage of a large high-resolution display to single or dual desktop displays for daily work. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 1005-1014. Available online
“With the ever increasing amount of digital information, users desire more screen real estate to process their daily computing work, and might well benefit from using a wall-size large high-resolution display instead of a desktop one. Unfortunately, we know very little about users' behaviors when using such a display for daily computing. We present a week-long study that investigates large display use in a personal desktop computing context by comparing it with single and dual desktop monitor use. Results show users' unanimous preference for using a large display: it facilitates multi-window and rich information tasks, enhances users' awareness of peripheral applications, and offers a more immersive experience. Further, the data reveals distinct usage patterns in partitioning screen real estate and managing windows on a large display. Detailed analysis of these results provides insights into designing interaction techniques and window management systems more suited to a large display.”
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Forlines, Clifton and Balakrishnan, Ravin (2009): Improving visual search with image segmentation. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 1093-1102. Available online
“People's ability to accurately locate target objects in images is severely affected by the prevalence of the sought objects. This negative effect greatly impacts critical real world tasks, such as baggage screening and cell slide pathology, in which target objects are rare. We present three novel image presentation techniques that are designed to improve visual search. Our techniques rely on the images being broken into image segments, which are then recombined or displayed in novel ways. The techniques and their underlying design reasoning are described in detail, and three experiments are presented that provide initial evidence that these techniques lead to better search performance in a simulated cell slide pathology task.”
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Findlater, Leah, Balakrishnan, Ravin and Toyama, Kentaro (2009): Comparing semiliterate and illiterate users' ability to transition from audio+text to text-only interaction. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 1751-1760. Available online
“Multimodal interfaces with little or no text have been shown to be useful for users with low literacy. However, this research has not differentiated between the needs of the fully illiterate and semiliterate -- those who have basic literacy but cannot read and write fluently. Text offers a fast and unambiguous mode of interaction for literate users and the exposure to text may allow for incidental improvement of reading skills. We conducted two studies that explore how semiliterate users with very little education might benefit from a combination of text and audio as compared to illiterate and literate users. Results show that semiliterate users reduced their use of audio support even during the first hour of use and over several hours this reduction was accompanied by a gain in visual word recognition; illiterate users showed no similar improvement. Semiliterate users should thus be treated differently from illiterate users in interface design.”
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Hinckley, Ken, Dixon, Morgan, Sarin, Raman, Guimbretiere, Francois and Balakrishnan, Ravin (2009): Codex: a dual screen tablet computer. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 1933-1942. Available online
“The Codex is a dual-screen tablet computer, about the size of a 4"x 6 day planner, with a self-supporting binding and embedded sensors. The device can be oriented in a variety of postures to support different nuances of individual work, ambient display, or collaboration with another user. In the context of a pen-operated note taking application, we demonstrate interaction techniques that support a fluid division of labor for tasks and information across the two displays while minimizing disruption to the primary experience of authoring notes.”
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Moraveji, Neema, Inkpen, Kori, Cutrell, Ed and Balakrishnan, Ravin (2009): A mischief of mice: examining children's performance in single display groupware systems with 1 to 32 mice. In: Proceedings of ACM CHI 2009 Conference on Human Factors in Computing Systems 2009. pp. 2157-2166. Available online
“Mischief is a system for classroom interaction that allows multiple children to use individual mice and cursors to interact with a single large display [20]. While the system can support large groups of children, it is unclear how children's performance is affected as group size increases. We explore this question via a study involving two tasks, with children working in group sizes ranging from 1 to 32. The first required reciprocal selection of two on-screen targets, resembling a swarm pointing scenario that might be used in educational applications. The second, a more temporally and spatially distributed pointing task, had children entering different words by selecting characters on an on-screen keyboard. Results indicate that performance is significantly affected by group size only when targets are small. Further, group size had a smaller effect when pointing was spatially and temporally distributed than when everyone was concurrently aiming at the same targets.”
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» 2008 «
Ranjan, Abhishek, Birnholtz, Jeremy and Balakrishnan, Ravin (2008): Improving meeting capture by applying television production principles with audio and motion detection. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 227-236. Available online
“Video recordings of meetings are often monotonous and tedious to watch. In this paper, we report on the design, implementation and evaluation of an automated meeting capture system that applies television production principles to capture and present videos of small group meetings in a compelling manner. The system uses inputs from a motion capture system and microphones to drive multiple pan-tilt-zoom cameras and uses heuristics to frame shots and cut between them. An evaluation of the system indicates that its performance approaches that of a professional crew while requiring significantly fewer human resources.”
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Dragicevic, Pierre, Ramos, Gonzalo, Bibliowitcz, Jacobo, Nowrouzezahrai, Derek, Balakrishnan, Ravin and Singh, Karan (2008): Video browsing by direct manipulation. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 237-246. Available online
“We present a method for browsing videos by directly dragging their content. This method brings the benefits of direct manipulation to an activity typically mediated by widgets. We support this new type of interactivity by: 1) automatically extracting motion data from videos; and 2) a new technique called relative flow dragging that lets users control video playback by moving objects of interest along their visual trajectory. We show that this method can outperform the traditional seeker bar in video browsing tasks that focus on visual content rather than time.”
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Grossman, Tovi and Balakrishnan, Ravin (2008): Collaborative interaction with volumetric displays. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 383-392. Available online
“Volumetric displays possess a number of unique properties which potentially make them particularly suitable for collaborative 3D applications. Because such displays have only recently become available, interaction techniques for collaborative usage have yet to be explored. In this paper, we initiate this exploration. We present a prototype collaborative 3D model viewing application, which served as a platform for our explorations. We outline three design goals, discuss the key interaction issues which were encountered, and describe a suite of new techniques in detail. In initial user observation sessions, we found that our techniques allowed users to successfully complete a variety of 3D tasks. Furthermore, interviews with experts in potential usage domains indicated that the techniques we developed can serve as a baseline for future collaborative applications for volumetric displays.”
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Saponas, T. Scott, Tan, Desney S., Morris, Dan and Balakrishnan, Ravin (2008): Demonstrating the feasibility of using forearm electromyography for muscle-computer interfaces. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 515-524. Available online
“We explore the feasibility of muscle-computer interfaces (muCIs): an interaction methodology that directly senses and decodes human muscular activity rather than relying on physical device actuation or user actions that are externally visible or audible. As a first step towards realizing the mu-CI concept, we conducted an experiment to explore the potential of exploiting muscular sensing and processing technologies for muCIs. We present results demonstrating accurate gesture classification with an off-the-shelf electromyography (EMG) device. Specifically, using 10 sensors worn in a narrow band around the upper forearm, we were able to differentiate position and pressure of finger presses, as well as classify tapping and lifting gestures across all five fingers. We conclude with discussion of the implications of our results for future muCI designs.”
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Forlines, Clifton and Balakrishnan, Ravin (2008): Evaluating tactile feedback and direct vs. indirect stylus input in pointing and crossing selection tasks. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1563-1572. Available online
“We present a pair of experiments that explore the effects of tactile-feedback and direct vs. indirect pen input on pointing and crossing selection tasks. While previous work has demonstrated the validity of crossing as a useful selection mechanism for pen-based computing, those experiments were conducted using an indirect input device -- one in which the pen-input and display were separated. We investigate users' performance with pointing and crossing interfaces controlled via not only an indirect input device, but also a direct input device -- one in which the pen-input and display are co-located. Results show that direct input significantly outperforms indirect input for crossing selection, but the two modalities are essentially equivalent in pointing selection. A small amount of tactile feedback is shown to be beneficial for both pointing and crossing selection, most noticeably in crossing tasks when using direct input where visual feedback is often occluded by a hand or stylus.”
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Cao, Xiang, Li, Jacky Jie and Balakrishnan, Ravin (2008): Peephole pointing: modeling acquisition of dynamically revealed targets. In: Proceedings of ACM CHI 2008 Conference on Human Factors in Computing Systems April 5-10, 2008. pp. 1699-1708. Available online
“Peephole interaction occurs when a spatially aware display is moved and acts as a viewport to reveal different parts of the virtual space that cannot all fit within the display at once. We investigate pointing within this peephole metaphor, where the targets may not be initially visible on the display, but are dynamically revealed by moving the display. We develop and experimentally validate a quantitative model for peephole pointing. Our results indicate that the model accurately accounts for peephole pointing for a variety of display sizes, both with and without users' having prior knowledge of the target location.”
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Cao, Xiang, Massimi, Michael and Balakrishnan, Ravin (2008): Flashlight jigsaw: an exploratory study of an ad-hoc multi-player game on public displays. In: Proceedings of ACM CSCW08 Conference on Computer-Supported Cooperative Work 2008. pp. 77-86. Available online
“As large displays become prevalent in public spaces, they could be employed to create novel game experiences for the public. We present an exploratory study of an ad-hoc multi-player game played on such public displays. The game, Flashlight Jigsaw, was deployed in a shared lab space and a public atrium for two weeks in total. Through interviews supported by observations and system logs we explored the experiences and behaviors of players and spectators. We also investigated the interrelationship between public display games and the spaces they are deployed in. The research resulted in findings regarding game play, communication, social interaction, spectatorship, and space and location around such a game. We use our findings to develop design implications for future public display games.”
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Cao, Xiang, Wilson, Andrew D., Balakrishnan, Ravin, Hinckley, Ken and Hudson, Scott E. (2008): ShapeTouch: Leveraging contact shape on interactive surfaces. In: Third IEEE International Workshop on Tabletops and Interactive Surfaces Tabletop 2008 October 1-3, 2008, Amsterdam, The Netherlands. pp. 129-136. Available online
Casiez, Géry, Vogel, Daniel, Balakrishnan, Ravin and Cockburn, Andy (2008): The Impact of Control-Display Gain on User Performance in Pointing Tasks. In Human-Computer Interaction, 23 (3) pp. 215-250
“We theoretically and empirically examine the impact of control display (CD) gain on mouse pointing performance. Two techniques for modifying CD gain are considered: constant gain (CG) where CD gain is uniformly adjusted by a constant multiplier, and pointer acceleration (PA) where CD gain is adjusted using a nonuniform function depending on movement characteristics. Both CG and PA are evaluated at various levels of relationship between mouse and cursor movement: from low levels, which have a near one-to-one mapping, through to high levels that aggressively amplify mouse movement. We further derive a model predicting the modification in motor-space caused by pointer acceleration. Experiments are then conducted on a standard desktop display and on a very large high-resolution display, allowing us to measure performance in high index of difficulty tasks where the effect of clutching may be pronounced. The evaluation apparatus was designed to minimize device quantization effects and used accurate 3D motion tracking equipment to analyze users' limb movements. On both displays, and in both gain techniques, we found that low levels of CD gain had a marked negative effect on performance, largely because of increased clutching and maximum limb speeds. High gain levels had relatively little impact on performance, with only a slight increase in time when selecting very small targets at high levels of constant gain. On the standard desktop display, pointer acceleration resulted in 3.3% faster pointing than constant gain and up to 5.6% faster with small targets. This supported the theoretical prediction of motor-space modification but fell short of the theoretical potential, possibly because PA caused an increase in target overshooting. Both techniques were accurately modeled by Fitts' law in all gain settings except for when there was a significant amount of clutching. From our results, we derive a usable range of CD gain settings between thresholds of speed and accuracy given the capabilities of a pointing device, display, and the expected range of target widths and distances.”
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Prasad, Archana, Medhi, Indrani, Toyama, Kentaro and Balakrishnan, Ravin (2008): Exploring the feasibility of video mail for illiterate users. In: Levialdi, Stefano (ed.) AVI 2008 - Proceedings of the working conference on Advanced Visual Interfaces May 28-30, 2008, Napoli, Italy. pp. 103-110. Available online
Bi, Xiaojun, Moscovich, Tomer, Ramos, Gonzalo, Balakrishnan, Ravin and Hinckley, Ken (2008): An exploration of pen rolling for pen-based interaction. In: Cousins, Steve B. and Beaudouin-Lafon, Michel (eds.) Proceedings of the 21st Annual ACM Symposium on User Interface Software and Technology October 19-22, 2008, Monterey, CA, USA. pp. 191-200. Available online
Benko, Hrvoje, Wilson, Andrew D. and Balakrishnan, Ravin (2008): Sphere: multi-touch interactions on a spherical display. In: Cousins, Steve B. and Beaudouin-Lafon, Michel (eds.) Proceedings of the 21st Annual ACM Symposium on User Interface Software and Technology October 19-22, 2008, Monterey, CA, USA. pp. 77-86. Available online
Bae, Seok-Hyung, Balakrishnan, Ravin and Singh, Karan (2008): ILoveSketch: as-natural-as-possible sketching system for creating 3d curve models. In: Cousins, Steve B. and Beaudouin-Lafon, Michel (eds.) Proceedings of the 21st Annual ACM Symposium on User Interface Software and Technology October 19-22, 2008, Monterey, CA, USA. pp. 151-160. Available online
Schmidt, Ryan, Singh, Karan and Balakrishnan, Ravin (2008): Sketching and Composing Widgets for 3D Manipulation. In Comput. Graph. Forum, 27 (2) pp. 301-310
» 2007 «
Birnholtz, Jeremy P., Grossman, Tovi, Mak, Clarissa and Balakrishnan, Ravin (2007): An exploratory study of input configuration and group process in a negotiation task using a large display. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 91-100. Available online
“This paper reports on an exploratory study of the effects of input configuration on group behavior and performance in a collaborative task performed by a collocated group using a large display. Twelve groups completed a mixed-motive negotiation task under two conditions: a single, shared mouse and one mouse per person. Results suggest that the multiple mouse condition allowed for more parallel work, but the quality of discussion was higher in the single mouse condition. Moreover, participants were more likely to act in their own best interest in the multiple mouse condition.”
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Grossman, Tovi, Kong, Nicholas and Balakrishnan, Ravin (2007): Modeling pointing at targets of arbitrary shapes. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 463-472. Available online
“We investigate pointing at graphical targets of arbitrary shapes. We first describe a previously proposed probabilistic Fitts' law model [7] which, unlike previous models that only account for rectangular targets, has the potential to handle arbitrary shapes. Three methods of defining the centers of arbitrarily shaped targets for use within the model are developed. We compare these methods of defining target centers, and validate the model using a pointing experiment in which the targets take on various shapes. Results show that the model can accurately account for the varying target shapes. We discuss the implications of our results to interface design.”
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Wigdor, Daniel, Shen, Chia, Forlines, Clifton and Balakrishnan, Ravin (2007): Perception of elementary graphical elements in tabletop and multi-surface environments. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 473-482. Available online
“Information shown on a tabletop display can appear distorted when viewed by a seated user. Even worse, the impact of this distortion is different depending on the location of the information on the display. In this paper, we examine how this distortion affects the perception of the basic graphical elements of information visualization shown on displays at various angles. We first examine perception of these elements on a single display, and then compare this to perception across displays, in order to evaluate the effectiveness of various elements for use in a tabletop and multi-display environment. We found that the perception of some graphical elements is more robust to distortion than others. We then develop recommendations for building data visualizations for these environments.”
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Grossman, Tovi, Wigdor, Daniel and Balakrishnan, Ravin (2007): Exploring and reducing the effects of orientation on text readability in volumetric displays. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 483-492. Available online
“Volumetric displays, which provide a 360° view of imagery illuminated in true 3D space, are a promising platform for interactive 3D applications. However, presenting text in volumetric displays can be a challenge, as the text may not be oriented towards the user. This is especially problematic with multiple viewers, as the text could, for example, appear forwards to one user, and backwards to another. In a first experiment we determined the effects of 3D rotations on text readability. Based on the results, we developed and evaluated a new technique which optimizes text orientation for multiple viewers. This technique provided 33% faster group reading times in a collaborative experimental task.”
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Forlines, Clifton, Wigdor, Daniel, Shen, Chia and Balakrishnan, Ravin (2007): Direct-touch vs. mouse input for tabletop displays. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 647-656. Available online
“We investigate the differences -- in terms of both quantitative performance and subjective preference -- between direct-touch and mouse input for unimanual and bimanual tasks on tabletop displays. The results of two experiments show that for bimanual tasks performed on tabletops, users benefit from direct-touch input. However, our results also indicate that mouse input may be more appropriate for a single user working on tabletop tasks requiring only single-point interaction.”
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Ramos, Gonzalo, Cockburn, Andy, Balakrishnan, Ravin and Beaudouin-Lafon, Michel (2007): Pointing lenses: facilitating stylus input through visual-and motor-space magnification. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 757-766. Available online
“Using a stylus on a tablet computer to acquire small targets can be challenging. In this paper we present pointing lenses -- interaction techniques that help users acquire and select targets by presenting them with an enlarged visual and interaction area. We present and study three pointing lenses for pen-based systems and find that our proposed Pressure-Activated Lens is the top overall performer in terms of speed, accuracy and user preference. In addition, our experimental results not only show that participants find all pointing lenses beneficial for targets smaller than 5 pixels, but they also suggest that this benefit may extend to larger targets as well.”
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Ranjan, Abhishek, Birnholtz, Jeremy P. and Balakrishnan, Ravin (2007): Dynamic shared visual spaces: experimenting with automatic camera control in a remote repair task. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 1177-1186. Available online
“We present an experimental study of automatic camera control in the performance of collaborative remote repair tasks using video-mediated communication. Twelve pairs of participants, one "helper" and one "worker," completed a series of Lego puzzle tasks using both a static camera and an automatic camera system that was guided in part by tracking the worker's hand position. Results show substantial performance benefits for the automatic system, particularly for complex tasks. The implications of these results are discussed, along with some lessons for the use of motion tracking as a driver for camera control.”
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Ramos, Gonzalo A. and Balakrishnan, Ravin (2007): Pressure marks. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 1375-1384. Available online
“Selections and actions in GUI's are often separated -- i.e. an action or command typically follows a selection. This sequence imposes a lower bound on the interaction time that is equal to or greater than the sum of its parts. In this paper, we introduce pressure marks -- pen strokes where the variations in pressure make it possible to indicate both a selection and an action simultaneously. We propose a series of design guidelines from which we develop a set of four basic types of pressure marks. We first assess the viability of this set through an exploratory study that looks at the way users draw straight and lasso pressure marks of different sizes and orientations. We then present the results of a quantitative experiment that shows that users perform faster selection-action interactions with pressure marks than with a combination of lassos and pigtails. Based on these results, we present and discuss a number of interaction designs that incorporate pressure marks.”
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Zhao, Shengdong, Dragicevic, Pierre, Chignell, Mark, Balakrishnan, Ravin and Baudisch, Patrick (2007): Earpod: eyes-free menu selection using touch input and reactive audio feedback. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 1395-1404. Available online
“We present the design and evaluation of earPod: an eyes-free menu technique using touch input and reactive auditory feedback. Studies comparing earPod with an iPod-like visual menu technique on reasonably-sized static menus indicate that they are comparable in accuracy. In terms of efficiency (speed), earPod is initially slower, but outperforms the visual technique within 30 minutes of practice. Our results indicate that earPod is potentially a reasonable eyes-free menu technique for general use, and is a particularly exciting technique for use in mobile device interfaces.”
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Grossman, Tovi, Dragicevic, Pierre and Balakrishnan, Ravin (2007): Strategies for accelerating on-line learning of hotkeys. In: Proceedings of ACM CHI 2007 Conference on Human Factors in Computing Systems 2007. pp. 1591-1600. Available online
“Hotkeys are extremely useful in leveraging expert performance, but learning them is a slow process. This paper investigates alternative menu designs that can motivate and help users remember associations between menu commands and hotkeys. Building upon previous work on paired-associate learning, we suggest that the transition to expert use can be accelerated by manipulating feedback and cost associated with menu selection. We evaluate five designs in a pilot study and then two of the most promising ones in a formal experiment, showing that the speed of hotkey learning can indeed be significantly increased with little modifications to the standard menu/hotkey paradigm.”
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Cao, Xiang, Forlines, Clifton and Balakrishnan, Ravin (2007): Multi-user interaction using handheld projectors. In: Proceedings of the ACM Symposium on User Interface Software and Technology October 7-10, 2007, Newport, Rhode Island, USA. pp. 43-52. Available online
“Recent research on handheld projector interaction has expanded the display and interaction space of handheld devices by projecting information onto the physical environment around the user, but has mainly focused on single-user scenarios. We extend this prior single-user research to co-located multi-user interaction using multiple handheld projectors. We present a set of interaction techniques for supporting co-located collaboration with multiple handheld projectors, and discuss application scenarios enabled by them.”
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» 2006 «
Wigdor, Daniel, Shen, Chia, Forlines, Clifton and Balakrishnan, Ravin (2006): Effects of display position and control space orientation on user preference and performance. In: Proceedings of ACM CHI 2006 Conference on Human Factors in Computing Systems 2006. pp. 309-318. Available online
“In many environments, it is often the case that input is made to displays that are positioned non-traditionally relative to one or more users. This typically requires users to perform interaction tasks under transformed input-display spatial mappings, and the literature is unclear as to how such transformations affect performance. We present two experiments that explore the impact of display space position and input control space orientation on user's subjective preference and objective performance in a docking task. Our results provide guidelines as to optimal display placement and control orientation in collaborative computing environments with one or more shared displays.”
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Ranjan, Abhishek, Balakrishnan, Ravin and Chignell, Mark (2006): Searching in audio: the utility of transcripts, dichotic presentation, and time-compression. In: Proceedings of ACM CHI 2006 Conference on Human Factors in Computing Systems 2006. pp. 721-730. Available online
“Searching audio data can potentially be facilitated by the use of automatic speech recognition (ASR) technology to generate text transcripts which can then be easily queried. However, since current ASR technology cannot reliably generate 100% accurate transcripts, additional techniques for fluid browsing and searching of the audio itself are required. We explore the impact of transcripts of various qualities, dichotic presentation, and time-compression on an audio search task. Results show that dichotic presentation and reasonably accurate transcripts can assist in the search process, but suggest that time-compression and low accuracy transcripts should be used carefully.”
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Grossman, Tovi, Hinckley, Ken, Baudisch, Patrick, Agrawala, Maneesh and Balakrishnan, Ravin (2006): Hover widgets: using the tracking state to extend the capabilities of pen-operated devices. In: Proceedings of ACM CHI 2006 Conference on Human Factors in Computing Systems 2006. pp. 861-870. Available online
“We present Hover Widgets, a new technique for increasing the capabilities of pen-based interfaces. Hover Widgets are implemented by using the pen movements above the display surface, in the tracking state. Short gestures while hovering, followed by a pen down, access the Hover Widgets, which can be used to activate localized interface widgets. By using the tracking state movements, Hover Widgets create a new command layer which is clearly distinct from the input layer of a pen interface. In a formal experiment Hover Widgets were found to be faster than a more traditional command activation technique, and also reduced errors due to divided attention.”
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Agarawala, Anand and Balakrishnan, Ravin (2006): Keepin' it real: pushing the desktop metaphor with physics, piles and the pen. In: Proceedings of ACM CHI 2006 Conference on Human Factors in Computing Systems 2006. pp. 1283-1292. Available online
“We explore making virtual desktops behave in a more physically realistic manner by adding physics simulation and using piling instead of filing as the fundamental organizational structure. Objects can be casually dragged and tossed around, influenced by physical characteristics such as friction and mass, much like we would manipulate lightweight objects in the real world. We present a prototype, called BumpTop, that coherently integrates a variety of interaction and visualization techniques optimized for pen input we have developed to support this new style of desktop organization.”
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Forlines, Clifton, Shen, Chia, Wigdor, Daniel and Balakrishnan, Ravin (2006): Exploring the effects of group size and display configuration on visual search. In: Proceedings of ACM CSCW06 Conference on Computer-Supported Cooperative Work 2006. pp. 11-20. Available online
“Visual search is the subject of countless psychology studies in which people search for target items within a scene. The bulk of this literature focuses on the individual with the goal of understanding the human perceptual system. In life, visual search is performed not only by individuals, but also by groups -- a team of doctors may study an x-ray and a team of analysts may study a satellite photograph. In this paper, we examine the issues one should consider when searching as a group. We present the details of an experiment designed to investigate the impact of group size on visual search performance, and how different display configurations affected that performance. We asked individuals, pairs, and groups of four people to participate in a baggage screening task in which these teams searched simulated x-rays for prohibited items. Teams conducted these searches on single monitors, a row of four monitors, and on a single horizontal display. Our findings suggest that groups commit far fewer errors in visual search tasks, although they may perform slower than individuals under certain conditions. The interaction between group size and display configuration turned out to be an important factor as well.”
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Ranjan, Abhishek, Birnholtz, Jeremy P. and Balakrishnan, Ravin (2006): An exploratory analysis of partner action and camera control in a video-mediated collaborative task. In: Proceedings of ACM CSCW06 Conference on Computer-Supported Cooperative Work 2006. pp. 403-412. Available online
“This paper reports on an exploratory experimental study of the relationships between physical movement and desired visual information in the performance of video-mediated collaborative tasks in the real world by geographically distributed groups. Twenty-three pairs of participants (one "helper" and one "worker") linked only by video and audio participated in a Lego construction task in one of three experimental conditions: a fixed scene camera, a helper-controlled pan-tilt-zoom camera, and a dedicated operator-controlled camera. "Worker" motion was tracked in 3-D space for all three conditions, as were all camera movements. Results suggest performance benefits for the operator-controlled condition, and the relationships between camera position/movement and worker action are explored to generate preliminary theoretical and design implications.”
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Grossman, Tovi and Balakrishnan, Ravin (2006): The design and evaluation of selection techniques for 3D volumetric displays. In: Proceedings of the ACM Symposium on User Interface Software and Technology 2006. pp. 3-12. Available online
“Volumetric displays, which display imagery in true 3D space, are a promising platform for the display and manipulation of 3D data. To fully leverage their capabilities, appropriate user interfaces and interaction techniques must be designed. In this paper, we explore 3D selection techniques for volumetric displays. In a first experiment, we find a ray cursor to be superior to a 3D point cursor in a single target environment. To address the difficulties associated with dense target environments we design four new ray cursor techniques which provide disambiguation mechanisms for multiple intersected targets. Our techniques showed varied success in a second, dense target experiment. One of the new techniques, the depth ray, performed particularly well, significantly reducing movement time, error rate, and input device footprint in comparison to the 3D point cursor.”
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Bezerianos, Anastasia, Dragicevic, Pierre and Balakrishnan, Ravin (2006): Mnemonic rendering: an image-based approach for exposing hidden changes in dynamic displays. In: Proceedings of the ACM Symposium on User Interface Software and Technology 2006. pp. 159-168. Available online
“Managing large amounts of dynamic visual information involves understanding changes happening out of the user's sight. In this paper, we show how current software does not adequately support users in this task, and motivate the need for a more general approach. We propose an image-based storage, visualization, and implicit interaction paradigm called mnemonic rendering that provides better support for handling visual changes. Once implemented on a system, mnemonic rendering techniques can benefit all applications. We explore its rich design space and discuss its expected benefits as well as limitations based on feedback from users of a small-screen and a wall-size prototype.”
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Forlines, Clifton, Vogel, Daniel and Balakrishnan, Ravin (2006): HybridPointing: fluid switching between absolute and relative pointing with a direct input device. In: Proceedings of the ACM Symposium on User Interface Software and Technology 2006. pp. 211-220. Available online
“We present HybridPointing, a technique that lets users easily switch between absolute and relative pointing with a direct input device such as a pen. Our design includes a new graphical element, the Trailing Widget, which remains "close at hand" but does not interfere with normal cursor operation. The use of visual feedback to aid the user's understanding of input state is discussed, and several novel visual aids are presented. An experiment conducted on a large, wall-sized display validates the benefits of HybridPointing under certain conditions. We also discuss other situations in which HybridPointing may be useful. Finally, we present an extension to our technique that allows for switching between absolute and relative input in the middle of a single drag-operation.”
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Cao, Xiang and Balakrishnan, Ravin (2006): Interacting with dynamically defined information spaces using a handheld projector and a pen. In: Proceedings of the ACM Symposium on User Interface Software and Technology 2006. pp. 225-234. Available online
“The recent trend towards miniaturization of projection technology indicates that handheld devices will soon have the ability to project information onto any surface, thus enabling interfaces that are not possible with current handhelds. We explore the design space of dynamically defining and interacting with multiple virtual information spaces embedded in a physical environment using a handheld projector and a passive pen tracked in 3D. We develop techniques for defining and interacting with these spaces, and explore usage scenarios.”
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Wigdor, Daniel, Leigh, Darren, Forlines, Clifton, Shipman, Samuel, Barnwell, John, Balakrishnan, Ravin and Shen, Chia (2006): Under the table interaction. In: Proceedings of the ACM Symposium on User Interface Software and Technology 2006. pp. 259-268. Available online
“We explore the design space of a two-sided interactive touch table, designed to receive touch input from both the top and bottom surfaces of the table. By combining two registered touch surfaces, we are able to offer a new dimension of input for co-located collaborative groupware. This design accomplishes the goal of increasing the relative size of the input area of a touch table while maintaining its direct-touch input paradigm. We describe the interaction properties of this two-sided touch table, report the results of a controlled experiment examining the precision of user touches to the underside of the table, and a series of application scenarios we developed for use on inverted and two-sided tables. Finally, we present a list of design recommendations based on our experiences and observations with inverted and two-sided tables.”
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Wu, Mike, Shen, Chia, Ryall, Kathy, Forlines, Clifton and Balakrishnan, Ravin (2006): Gesture Registration, Relaxation, and Reuse for Multi-Point Direct-Touch Surfaces. In: First IEEE International Workshop on Horizontal Interactive Human-Computer Systems Tabletop 2006 5-7 January, 2006, Adelaide, Australia. pp. 185-192. Available online
Grossman, Tovi and Balakrishnan, Ravin (2006): An evaluation of depth perception on volumetric displays. In: Celentano, Augusto (ed.) AVI 2006 - Proceedings of the working conference on Advanced visual interfaces May 23-26, 2006, Venezia, Italy. pp. 193-200. Available online
Wigdor, Daniel, Shen, Chia, Forlines, Clifton and Balakrishnan, Ravin (2006): Table-centric interactive spaces for real-time collaboration. In: Celentano, Augusto (ed.) AVI 2006 - Proceedings of the working conference on Advanced visual interfaces May 23-26, 2006, Venezia, Italy. pp. 103-107. Available online
» 2005 «
Vogel, Daniel and Balakrishnan, Ravin (2005): Distant freehand pointing and clicking on very large, high resolution displays. In: Proceedings of the 2005 ACM Symposium on User Interface Software and Technology 2005. pp. 33-42. Available online
“We explore the design space of freehand pointing and clicking interaction with very large high resolution displays from a distance. Three techniques for gestural pointing and two for clicking are developed and evaluated. In addition, we present subtle auditory and visual feedback techniques to compensate for the lack of kinesthetic feedback in freehand interaction, and to promote learning and use of appropriate postures.”
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Malik, Shahzad, Ranjan, Abhishek and Balakrishnan, Ravin (2005): Interacting with large displays from a distance with vision-tracked multi-finger gestural input. In: Proceedings of the 2005 ACM Symposium on User Interface Software and Technology 2005. pp. 43-52. Available online
“We explore the idea of using vision-based hand tracking over a constrained tabletop surface area to perform multi-finger and whole-hand gestural interactions with large displays from a distance. We develop bimanual techniques to support a variety of asymmetric and symmetric interactions, including fast targeting and navigation to all parts of a large display from the comfort of a desk and chair, as well as techniques that exploit the ability of the vision-based hand tracking system to provide multi-finger identification and full 2D hand segmentation. We also posit a design that allows for handling multiple concurrent users.”
Copyrights may apply
Forlines, Clifton, Balakrishnan, Ravin, Beardsley, Paul, Baar, Jeroen van and Raskar, Ramesh (2005): Zoom-and-pick: facilitating visual zooming and precision pointing with interactive handheld projectors. In: Proceedings of the 2005 ACM Symposium on User Interface Software and Technology 2005. pp. 73-82. Available online
“Designing interfaces for interactive handheld projectors is an exiting new area of research that is currently limited by two problems: hand jitter resulting in poor input control, and possible reduction of image resolution due to the needs of image stabilization and warping algorithms. We present the design and evaluation of a new interaction technique, called zoom-and-pick, that addresses both problems by allowing the user to fluidly zoom in on areas of interest and make accurate target selections. Subtle design features of zoom-and-pick enable pixel-accurate pointing, which is not possible in most freehand interaction techniques. Our evaluation results indicate that zoom-and-pick is significantly more accurate than the standard pointing technique described in our previous work.”
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Ramos, Gonzalo and Balakrishnan, Ravin (2005): Zliding: fluid zooming and sliding for high precision parameter manipulation. In: Proceedings of the 2005 ACM Symposium on User Interface Software and Technology 2005. pp. 143-152. Available online
“High precision parameter manipulation tasks typically require adjustment of the scale of manipulation in addition to the parameter itself. This paper introduces the notion of Zoom Sliding, or Zliding, for fluid integrated manipulation of scale (zooming) via pressure input while parameter manipulation within that scale is achieved via x-y cursor movement (sliding). We also present the Zlider (Figure 1), a widget that instantiates the Zliding concept. We experimentally evaluate three different input techniques for use with the Zlider in conjunction with a stylus for x-y cursor positioning, in a high accuracy zoom and select task. Our results marginally favor the stylus with integrated isometric pressure sensing tip over bimanual techniques which separate zooming and sliding controls over the two hands. We discuss the implications of our results and present further designs that make use of Zliding.”
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Cao, Xiang and Balakrishnan, Ravin (2005): Evaluation of an on-line adaptive gesture interface with command prediction. In: Graphics Interface 2005 May 9-11, 2005, Victoria, British Columbia, Canada. pp. 187-194. Available online
“We present an evaluation of a hybrid gesture interface framework that combines on-line adaptive gesture recognition with a command predictor. Machine learning techniques enable on-line adaptation to differences in users' input patterns when making gestures, and exploit regularities in command sequences to improve recognition performance. A prototype using 2D single-stroke gestures was implemented with a minimally intrusive user interface for on-line re-training. Results of a controlled user experiment show that the hybrid adaptive system significantly improved overall gesture recognition performance, and reduced users' need to practice making the gestures before achieving good results.”
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Grossman, Tovi and Balakrishnan, Ravin (2005): The bubble cursor: enhancing target acquisition by dynamic resizing of the cursor's activation area. In: Proceedings of ACM CHI 2005 Conference on Human Factors in Computing Systems 2005. pp. 281-290. Available online
“We present the bubble cursor - a new target acquisition technique based on area cursors. The bubble cursor improves upon area cursors by dynamically resizing its activation area depending on the proximity of surrounding targets, such that only one target is selectable at any time. We also present two controlled experiments that evaluate bubble cursor performance in 1D and 2D target acquisition tasks, in complex situations with multiple targets of varying layout densities. Results show that the bubble cursor significantly outperforms the point cursor and the object pointing technique [7], and that bubble cursor performance can be accurately modeled and predicted using Fitts' law.”
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Bezerianos, Anastasia and Balakrishnan, Ravin (2005): The vacuum: facilitating the manipulation of distant objects. In: Proceedings of ACM CHI 2005 Conference on Human Factors in Computing Systems 2005. pp. 361-370. Available online
“We present the design and evaluation of the vacuum, a new interaction technique that enables quick access to items on areas of a large display that are difficult for a user to reach without significant physical movement. The vacuum is a circular widget with a user controllable arc of influence that is centered at the widget's point of invocation and spans out to the edges of the display. Far away objects residing inside this influence arc are brought closer to the widget's centre in the form of proxies that can be manipulated in lieu of the original. We conducted two experiments which compare the vacuum to direct picking and an existing technique called drag-and-pick [2]. Results show that the vacuum outperforms existing techniques when selecting multiple targets in a sequence, performs similarly to existing techniques when selecting single targets located moderately far away, and slightly worse with single targets located very far away in the presence of distracter targets along the path.”
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Bezerianos, Anastasia and Balakrishnan, Ravin (2005): Canvas Portals: View and Space Management on Large Displays.. In IEEE Computer Graphics & Applications, Special Issue on Applications of Large Displays, 25 (4) pp. 34-43
McGuffin, Michael J. and Balakrishnan, Ravin (2005): Interactive Visualization of Genealogical Graphs. In: InfoVis 2005 - IEEE Symposium on Information Visualization 23-25 October, 2005, Minneapolis, MN, USA. p. 3. Available online
» 2004 «
Wigdor, Daniel and Balakrishnan, Ravin (2004): A comparison of consecutive and concurrent input text entry techniques for mobile phones. In: Dykstra-Erickson, Elizabeth and Tscheligi, Manfred (eds.) Proceedings of ACM CHI 2004 Conference on Human Factors in Computing Systems April 24-29, 2004, Vienna, Austria. pp. 81-88. Available online
“The numeric keypads on mobile phones generally consist of 12 keys (0-9, *, #). Ambiguity arises when the 36-character alpha-numeric English alphabet is mapped onto this smaller number of keys. In this paper, we first present a taxonomy of the various techniques for resolving this ambiguity, dividing them into techniques that use consecutive actions to first select a character grouping and then a character from within that grouping, and those that use concurrent actions to achieve the same end. We then present the design and implementation of a chording approach to text entry that uses concurrent key presses. We conducted a controlled experiment that compared this chording technique to one-handed and two-handed versions of the commonly used MultiTap technique. The results show that the concurrent chording technique significantly outperforms both versions of the consecutive action MultiTap technique.”
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Grossman, Tovi and Balakrishnan, Ravin (2004): Pointing at trivariate targets in 3D environments. In: Dykstra-Erickson, Elizabeth and Tscheligi, Manfred (eds.) Proceedings of ACM CHI 2004 Conference on Human Factors in Computing Systems April 24-29, 2004, Vienna, Austria. pp. 447-454. Available online
“We investigate pointing in true 3D environments where the target size varies in three spatial dimensions. We also study the effect of the user's physical movement angle on pointing performance. Results show that target size dimension along the primary axis of movement has a greater impact on performance than the other two dimensions. Movement angle also significantly affects performance, and changes the relative impact of the three target dimensions. Building upon recent results in the modeling of bivariate pointing, we propose and validate a new model that describes pointing at trivariate targets. This model also accounts for movement angle, and outperforms previously published models.”
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Ramos, Gonzalo, Boulos, Matthew and Balakrishnan, Ravin (2004): Pressure widgets. In: Dykstra-Erickson, Elizabeth and Tscheligi, Manfred (eds.) Proceedings of ACM CHI 2004 Conference on Human Factors in Computing Systems April 24-29, 2004, Vienna, Austria. pp. 487-494. Available online
“Current user interface widgets typically assume that the input device can only provide x-y position and binary button press information. Other inputs such as the continuous pressure data provided by styluses on tablets are rarely used. We explore the design space of using the continuous pressure sensing capabilities of styluses to operate multi-state widgets. We present the results of a controlled experiment that investigates human ability to perform discrete target selection tasks by varying a stylus' pressure, with full or partial visual feedback. The experiment also considers different techniques for confirming selection once the target is acquired. Based on the experimental results, we discuss implications for the design of pressure sensitive widgets. A taxonomy of pressure widgets is presented, along with a set of initial concept sketches of various pressure widget designs.”
Copyrights may apply
Tsang, Steve, Balakrishnan, Ravin, Singh, Karan and Ranjan, Abhishek (2004): A suggestive interface for image guided 3D sketching. In: Dykstra-Erickson, Elizabeth and Tscheligi, Manfred (eds.) Proceedings of ACM CHI 2004 Conference on Human Factors in Computing Systems April 24-29, 2004, Vienna, Austria. pp. 591-598. Available online
“We present an image guided pen-based suggestive interface for sketching 3D wireframe models. Rather than starting from a blank canvas, existing 2D images of similar objects serve as a guide to the user. Image based filters enable attraction, smoothing, and resampling of input curves, and allows for their selective application using pinning and gluing techniques. New input strokes also invoke suggestions of relevant geometry that can be used, reducing the need to explicitly draw all parts of the new model. All suggestions appear in-place with the model being built, in the user's focal attention space. A curve matching algorithm seamlessly augments basic suggestions with more complex ones from a database populated with previously used geometry. The interface also incorporates gestural command input, and interaction techniques for camera controls that enable smooth transitions between orthographic and perspective views.”
Copyrights may apply
Zhao, Shengdong and Balakrishnan, Ravin (2004): Simple vs. compound mark hierarchical marking menus. In: Proceedings of the 2004 ACM Symposium on User Interface Software and Technology 2004. pp. 33-42. Available online
“We present a variant of hierarchical marking menus where items are selected using a series of inflection-free simple marks, rather than the single \"zig-zag\" compound mark used in the traditional design. Theoretical analysis indicates that this simple mark approach has the potential to significantly increase the number of items in a marking menu that can be selected efficiently and accurately. A user experiment is presented that compares the simple and compound mark techniques. Results show that the simple mark technique allows for significantly more accurate and faster menu selections overall, but most importantly also in menus with a large number of items where performance of the compound mark technique is particularly poor. The simple mark technique also requires significantly less physical input space to perform the selections, making it particularly suitable for small footprint pen-based input devices. Visual design alternatives are also discussed.”
Copyrights may apply
Grossman, Tovi, Wigdor, Daniel and Balakrishnan, Ravin (2004): Multi-finger gestural interaction with 3d volumetric displays. In: Proceedings of the 2004 ACM Symposium on User Interface Software and Technology 2004. pp. 61-70. Available online
“Volumetric displays provide interesting opportunities and challenges for 3D interaction and visualization, particularly when used in a highly interactive manner. We explore this area through the design and implementation of techniques for interactive direct manipulation of objects with a 3D volumetric display. Motion tracking of the user\'s fingers provides for direct gestural interaction with the virtual objects, through manipulations on and around the display\'s hemispheric enclosure. Our techniques leverage the unique features of volumetric displays, including a 360{deg} viewing volume that enables manipulation from any viewpoint around the display, as well as natural and accurate perception of true depth information in the displayed 3D scene. We demonstrate our techniques within a prototype 3D geometric model building application.”
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Vogel, Daniel and Balakrishnan, Ravin (2004): Interactive public ambient displays: transitioning from implicit to explicit, public to personal, interaction with multiple users. In: Proceedings of the 2004 ACM Symposium on User Interface Software and Technology 2004. pp. 137-146. Available online
“We develop design principles and an interaction framework for sharable, interactive public ambient displays that support the transition from implicit to explicit interaction with both public and personal information. A prototype system implementation that embodies these design principles is described. We use novel display and interaction techniques such as simple hand gestures and touch screen input for explicit interaction and contextual body orientation and position cues for implicit interaction. Techniques are presented for subtle notification, self-revealing help, privacy controls, and shared use by multiple people each in their own context. Initial user feedback is also presented, and future directions discussed.”
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Balakrishnan, Ravin (2004): "Beating" Fitts' law: virtual enhancements for pointing facilitation. In International Journal of Human-Computer Studies, 61 (6) pp. 857-874
“We survey recent research into new techniques for artificially facilitating pointing at targets in graphical user interfaces. While pointing in the physical world is governed by Fitts' law and constrained by physical laws, pointing in the virtual world does not necessarily have to abide by the same constraints, opening the possibility for "beating" Fitts' law with the aid of the computer by artificially reducing the target distance, increasing the target width, or both. The survey suggests that while the techniques developed to date are promising, particularly when applied to the selection of single isolated targets, many of them do not scale well to the common situation in graphical user interfaces where multiple targets are located in close proximity.”
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Aboelsaadat, W. and Balakrishnan, Ravin (2004): An Empirical Comparison of Transparency on One and Two Layer Displays. In: Proceedings of the HCI04 Conference on People and Computers XVIII 2004. pp. 53-68.
Tsang, Michael, Morris, Nigel and Balakrishnan, Ravin (2004): Temporal Thumbnails: rapid visualization of time-based viewing data. In: Costabile, Maria Francesca (ed.) AVI 2004 - Proceedings of the working conference on Advanced visual interfaces May 25-28, 2004, Gallipoli, Italy. pp. 175-178. Available online
McGuffin, Michael J., Davison, Gord and Balakrishnan, Ravin (2004): Expand-Ahead: A Space-Filling Strategy for Browsing Trees. In: InfoVis 2004 - 10th IEEE Symposium on Information Visualization 10-12 October, 2004, Austin, TX, USA. pp. 119-126. Available online
» 2003 «
Grossman, Tovi, Balakrishnan, Ravin and Singh, Karan (2003): An interface for creating and manipulating curves using a high degree-of-freedom curve input device. In: Cockton, Gilbert and Korhonen, Panu (eds.) Proceedings of the ACM CHI 2003 Human Factors in Computing Systems Conference April 5-10, 2003, Ft. Lauderdale, Florida, USA. pp. 185-192.
Wigdor, Daniel and Balakrishnan, Ravin (2003): TiltText: using tilt for text input to mobile phones. In: Proceedings of the 16th annural ACM Symposium on User Interface Software and Technology November, 2-5, 2003, Vancouver, Canada. pp. 81-90. Available online
“TiltText, a new technique for entering text into a mobile phone is
described. The standard 12-button text entry keypad of a mobile phone forces
ambiguity when the 26- letter Roman alphabet is mapped in the traditional
manner onto keys 2-9. The TiltText technique uses the orientation of the phone
to resolve this ambiguity, by tilting the phone in one of four directions to
choose which character on a particular key to enter. We first discuss
implementation strategies, and then present the results of a controlled
experiment comparing TiltText to MultiTap, the most common text entry
technique. The experiment included 10 participants who each entered a total of
640 phrases of text chosen from a standard corpus, over a period of about five
hours. The results show that text entry speed including correction for errors
using TiltText was 23% faster than MultiTap by the end of the experiment,
despite a higher error rate for TiltText. TiltText is thus amongst the fastest
known language-independent techniques for entering text into mobile phones.”
Copyrights may apply
Ramos, Gonzalo and Balakrishnan, Ravin (2003): Fluid interaction techniques for the control and annotation of digital video. In: Proceedings of the 16th annural ACM Symposium on User Interface Software and Technology November, 2-5, 2003, Vancouver, Canada. pp. 105-114. Available online
“We explore a variety of interaction and visualization techniques for fluid
navigation, segmentation, linking, and annotation of digital videos. These
techniques are developed within a concept prototype called LEAN that is
designed for use with pressure-sensitive digitizer tablets. These techniques
include a transient position+velocity widget that allows users not only to move
around a point of interest on a video, but also to rewind or fast forward at a
controlled variable speed. We also present a new variation of fish-eye views
called twist-lens, and incorporate this into a position control slider designed
for the effective navigation and viewing of large sequences of video frames. We
also explore a new style of widgets that exploit the use of the pen's
pressure-sensing capability, increasing the input vocabulary available to the
user. Finally, we elaborate on how annotations referring to objects that are
temporal in nature, such as video, may be thought of as links, and fluidly
constructed, visualized and navigated.”
Copyrights may apply
Cao, Xiang and Balakrishnan, Ravin (2003): VisionWand: interaction techniques for large displays using a passive wand tracked in 3D. In: Proceedings of the 16th annural ACM Symposium on User Interface Software and Technology November, 2-5, 2003, Vancouver, Canada. pp. 173-182. Available online
“A passive wand tracked in 3D using computer vision techniques is explored as
a new input mechanism for interacting with large displays. We demonstrate a
variety of interaction techniques that exploit the affordances of the wand,
resulting in an effective interface for large scale interaction. The lack of
any buttons or other electronics on the wand presents a challenge that we
address by developing a set of postures and gestures to track state and enable
command input. We also describe the use of multiple wands, and posit designs
for more complex wands in the future.”
Copyrights may apply
Wu, Mike and Balakrishnan, Ravin (2003): Multi-finger and whole hand gestural interaction techniques for multi-user tabletop displays. In: Proceedings of the 16th annural ACM Symposium on User Interface Software and Technology November, 2-5, 2003, Vancouver, Canada. pp. 193-202. Available online
“Recent advances in sensing technology have enabled a new generation of
tabletop displays that can sense multiple points of input from several users
simultaneously. However, apart from a few demonstration techniques [17],
current user interfaces do not take advantage of this increased input
bandwidth. We present a variety of multifinger and whole hand gestural
interaction techniques for these displays that leverage and extend the types of
actions that people perform when interacting on real physical tabletops. Apart
from gestural input techniques, we also explore interaction and visualization
techniques for supporting shared spaces, awareness, and privacy. These
techniques are demonstrated within a prototype room furniture layout
application, called RoomPlanner.”
Copyrights may apply
McGuffin, Michael J., Tancau, Liviu and Balakrishnan, Ravin (2003): Using Deformations for Browsing Volumetric Data. In: Turk, Greg, Wijk, Jarke J. van and II, Robert J. Moorhead (eds.) 14th IEEE Visualization 2003 Conference VIS 2003 19-24 October, 2003, Seattle, WA, USA. pp. 401-408.
» 2002 «
McGuffin, Michael and Balakrishnan, Ravin (2002): Acquisition of expanding targets. In: Terveen, Loren (ed.) Proceedings of the ACM CHI 2002 Conference on Human Factors in Computing Systems Conference April 20-25, 2002, Minneapolis, Minnesota. pp. 57-64.
Grossman, Tovi, Balakrishnan, Ravin, Kurtenbach, Gordon, Fitzmaurice, George W., Khan, Azam and Buxton, Bill (2002): Creating principal 3D curves with digital tape drawing. In: Terveen, Loren (ed.) Proceedings of the ACM CHI 2002 Conference on Human Factors in Computing Systems Conference April 20-25, 2002, Minneapolis, Minnesota. pp. 121-128.
Burtnyk, Nicholas, Khan, Azam, Fitzmaurice, George W., Balakrishnan, Ravin and Kurtenbach, Gordon (2002): StyleCam: interactive stylized 3D navigation using integrated spatial & temporal controls. In: Beaudouin-Lafon, Michel (ed.) Proceedings of the 15th annual ACM symposium on User interface software and technology October 27-30, 2002, Paris, France. pp. 101-110. Available online
“This paper describes StyleCam, an approach for authoring 3D viewing
experiences that incorporate stylistic elements that are not available in
typical 3D viewers. A key aspect of StyleCam is that it allows the author to
significantly tailor what the user sees and when they see it. The resulting
viewing experience can approach the visual richness and pacing of highly
authored visual content such as television commercials or feature films. At the
same time, StyleCam allows for a satisfying level of interactivity while
avoiding the problems inherent in using unconstrained camera models. The main
components of StyleCam are camera surfaces which spatially constrain the
viewing camera; animation clips that allow for visually appealing transitions
between different camera surfaces; and a simple, unified, interaction technique
that permits the user to seamlessly and continuously move between
spatial-control of the camera and temporal-control of the animated transitions.
Further, the user's focus of attention is always kept on the content, and not
on extraneous interface widgets. In addition to describing the conceptual model
of StyleCam, its current implementation, and an example authored experience, we
also present the results of an evaluation involving real users.”
Copyrights may apply
» 2001 «
Balakrishnan, Ravin, Fitzmaurice, George W. and Kurtenbach, Gordon (2001): User Interfaces for Volumetric Displays. In IEEE Computer, 34 (3) pp. 37-45
» 2000 «
Balakrishnan, Ravin and Hinckley, Ken (2000): Symmetric Bimanual Interaction. In: Turner, Thea, Szwillus, Gerd, Czerwinski, Mary, Peterno, Fabio and Pemberton, Steven (eds.) Proceedings of the ACM CHI 2000 Human Factors in Computing Systems Conference April 1-6, 2000, The Hague, The Netherlands. pp. 33-40. Available online
“We present experimental work that explores the factors governing symmetric bimanual interaction in a two-handed task that requires the user to track a pair of targets, one target with each hand. A symmetric bimanual task is a two-handed task in which each hand is assigned an identical role. In this context, we explore three main experimental factors. We vary the distance between the pair of targets to track: as the targets become further apart, visual diversion increases, forcing the user to divide attention between the two targets. We also vary the demands of the task by using both a slow and a fast tracking speed. Finally, we explore visual integration of sub-tasks: in one condition, the two targets to track are connected by a line segment which visually links the targets, while in the other condition there is no connecting line. Our results indicate that all three experimental factors affect the degree of parallelism, which we quantify using a new metric of bimanual parallelism. However, differences in tracking error between the two hands are affected only by the visual integration factor.”
Copyrights may apply
» 1999 «
Balakrishnan, Ravin and Kurtenbach, Gordon (1999): Exploring Bimanual Camera Control and Object Manipulation in 3D Graphics Interfaces. In: Altom, Mark W. and Williams, Marian G. (eds.) Proceedings of the ACM CHI 99 Human Factors in Computing Systems Conference May 15-20, 1999, Pittsburgh, Pennsylvania. pp. 56-63. Available online
“We explore the use of the non-dominant hand to control a virtual camera while the dominant hand performs other tasks in a virtual 3D scene. Two experiments and an informal study are presented which evaluate this interaction style by comparing it to the status-quo unimanual interaction. In the first experiment, we find that for a target selection task, performance using the bimanual technique was 20% faster. Experiment 2 compared performance in a more complicated object docking task. Performance advantages are shown, however, only after practice. Free-form 3D painting was explored in the user study. In both experiments and in the user study participants strongly preferred the bimanual technique. The results also indicate that user preferences concerning bimanual interaction may be driven by factors other than simple time-motion performance advantages.”
Copyrights may apply
Fitzmaurice, George W., Balakrishnan, Ravin, Kurtenbach, Gordon and Buxton, Bill (1999): An Exploration into Supporting Artwork Orientation in the User Interface. In: Altom, Mark W. and Williams, Marian G. (eds.) Proceedings of the ACM CHI 99 Human Factors in Computing Systems Conference May 15-20, 1999, Pittsburgh, Pennsylvania. pp. 167-174. Available online
“Rotating a piece of paper while drawing is an integral and almost subconscious part of drawing with pencil and paper. In a similar manner, the advent of lightweight pen-based computers allow digital artwork to be rotated while drawing by rotating the entire computer. Given this type of manipulation we explore the implications for the user interface to support artwork orientation. First we describe an exploratory study to further motivate our work and characterize how artwork is manipulated while drawing. After presenting some possible UI approaches to support artwork orientation, we define a new solution called a rotating user interface (RUIs). We then discuss design issues and requirements for RUIs based on our exploratory study.”
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Balakrishnan, Ravin, Fitzmaurice, George W., Kurtenbach, Gordon and Buxton, William (1999): Digital Tape Drawing. In: Zanden, Brad Vander and Marks, Joe (eds.) Proceedings of the 12th annual ACM symposium on User interface software and technology November 07 - 10, 1999, Asheville, North Carolina, United States. pp. 161-169. Available online
“Tape drawing is the art of creating sketches on large scale upright surfaces using black photographic tape. Typically used in the automotive industry, it is an important part of the automotive design process that is currently not computerized. We analyze and describe the unique aspects of tape drawing, and use this knowledge to design and implement a digital tape drawing system. Our system retains the fundamental interaction and visual affordances of the traditional media while leveraging the power of the digital media. Aside from the practical aspect of our work, the interaction techniques developed have interesting implications for current theories of human bimanual interaction.”
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Balakrishnan, Ravin and Hinckley, Ken (1999): The Role of Kinesthetic Reference Frames in Two-Handed Input Performance. In: Zanden, Brad Vander and Marks, Joe (eds.) Proceedings of the 12th annual ACM symposium on User interface software and technology November 07 - 10, 1999, Asheville, North Carolina, United States. pp. 171-178. Available online
“We present experimental work which explores how the match (or mismatch) between the input space of the hands and the output space of a graphical display influences two-handed input performance. During interaction with computers, a direct correspondence between the input and output spaces is often lacking. Not only are the hands disjoint from the display space, but the reference frames of the hands may in fact be disjoint from one another if two separate input devices (e.g. two mice) are used for two-handed input. In general, we refer to the workspace and origin within which the hands operate as kinesthetic reference frames. Our goal is to better understand how an interface designer's choice of kinesthetic reference frames influences a user's ability to coordinate two-handed movements, and to explore how the answer to this question may depend on the availability of visual feedback. Understanding this issue has implications for the design of two-handed interaction techniques and input devices, as well as for the reference principle of Guiard's Kinematic Chain model of human bimanual action. Our results suggest that the Guiard reference principle is robust with respect to variances in the kinesthetic reference frames as long as appropriate visual feedback is present.”
Copyrights may apply
Fitzmaurice, George W., Balakrishnan, Ravin and Kurtenbach, Gordon (1999): Sampling, Synthesis, and Input Devices. In Communications of the ACM, 42 (8) pp. 54-63
» 1998 «
Balakrishnan, Ravin and Patel, Pranay (1998): The PadMouse: Facilitating Selection and Spatial Positioning for the Non-Dominant Hand. In: Karat, Clare-Marie, Lund, Arnold, Coutaz, Joëlle and Karat, John (eds.) Proceedings of the ACM CHI 98 Human Factors in Computing Systems Conference April 18-23, 1998, Los Angeles, California. pp. 9-16. Available online
“A new input device called the PadMouse is described and evaluated. The PadMouse consists of a two degree-of-freedom touchpad mounted on a regular mouse base. Like the regular mouse, the PadMouse allows for spatial positioning tasks to be performed by moving the device on a planar surface. In addition, when coupled with an interaction technique we call Marking Keys, users can use the touchpad to activate modifiers and commands. An experiment shows that up to 32 modifiers/commands can be quickly and accurately activated using this technique, making it a viable device for the non-dominant hand in two-handed user interfaces. Other uses for the PadMouse and design alternatives are also discussed.”
Copyrights may apply
» 1997 «
Balakrishnan, Ravin and MacKenzie, I. Scott (1997): Performance Differences in the Fingers, Wrist, and Forearm in Computer Input Control. In: Pemberton, Steven (ed.) Proceedings of the ACM CHI 97 Human Factors in Computing Systems Conference March 22-27, 1997, Atlanta, Georgia. pp. 303-310. Available online
“Recent work in computer input control has sought to maximize the use of the fingers in the operation of computer pointing devices. The main rationale is the hypothesis that the muscle groups controlling the fingers have a higher bandwidth than those controlling other segments of the human upper limb. Evidence which supports this, however, is inconclusive. We conducted an experiment to determine the relative bandwidths of the fingers, wrist, and forearm and found that the fingers do not necessarily outperform the other limb segments. Our results indicate that the bandwidth of the unsupported index finger is approximately 3.0 bits/s while the wrist and forearm have bandwidths of about 4.1 bits/s. We also show that the thumb and index finger working together in a pinch grip have an information processing rate of about 4.5 bits/s. Other factors which influence the relative performance of the different limbs in manipulation tasks are considered.”
Copyrights may apply
Balakrishnan, Ravin, Baudel, Thomas, Kurtenbach, Gordon and Fitzmaurice, George W. (1997): The Rockin' Mouse: Integral 3D Manipulation on a Plane. In: Pemberton, Steven (ed.) Proceedings of the ACM CHI 97 Human Factors in Computing Systems Conference March 22-27, 1997, Atlanta, Georgia. pp. 311-318. Available online
“A novel input device called the Rockin'Mouse is described and evaluated. The Rockin'Mouse is a four degree-of-freedom input device that has the same shape as a regular mouse except that the bottom of the Rockin'Mouse is rounded so that it can be tilted. This tilting can be used to control two extra degrees of freedom, thus making it suitable for manipulation in 3D environments. Like the regular mouse, the Rockin'Mouse can sense planar position and perform all the usual functions. However, in a 3D scene a regular mouse can only operate on 2 dimensions at a time and therefore manipulation in 3D requires a way to switch between dimensions. With the Rockin'Mouse, however, all the dimensions can be simultaneously controlled. In this paper we describe our design rationale behind the Rockin'Mouse, and present an experiment which compares the Rockin'Mouse to the standard mouse in a typical 3D interaction task. Our results indicate that the Rockin'Mouse is 30% faster and is a promising device for both 2D and 3D interaction.”
Copyrights may apply
» 1994 «
Ware, Colin and Balakrishnan, Ravin (1994): Reaching for Objects in VR Displays: Lag and Frame Rate. In ACM Transactions on Computer-Human Interaction, 1 (4) pp. 331-356
“This article reports the results from three experimental studies of reaching behavior in a head-coupled stereo display system with a hand-tracking subsystem for object selection. It is found that lag in the head-tracking system is relatively unimportant in predicting performance, whereas lag in the hand-tracking system is critical. The effect of hand lag can be modeled by means of a variation on Fitts' Law with the measured system lag introduced as a multiplicative variable to the Fitts' Law index of difficulty. This means that relatively small lags can cause considerable degradation in performance if the targets are small. Another finding is that errors are higher for movement in and out of the screen, as compared to movements in the plane of the screen, and”
Copyrights may apply
Ware, Colin and Balakrishnan, Ravin (1994): Target acquisition in fish tank VR: The effects of lag and frame rate. In: Graphics Interface 94 May 18-20, 1994, Banff, Alberta, Canada. pp. 1-7.
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Mar 21st, 2010
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